Vanadium-based pro-catalysts bearing depleted 1,3-calix[4]arenes for ethylene or ε-caprolactone polymerization

Clowes, Lucy, Redshaw, Carl and Hughes, David L. (2011) Vanadium-based pro-catalysts bearing depleted 1,3-calix[4]arenes for ethylene or ε-caprolactone polymerization. Inorganic Chemistry. 7838–7845. ISSN 0020-1669

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Abstract

Reaction of [V(X)(OR)3] (X = O, Np-tolyl, R = nPr, tBu) with 5,11,17,23-tBu-25,27-dihydroxycalix[4]arene (LH2) led to the formation of [V(X)(OR)L]2 X = O, R = nPr ( 1 ); X = Np-tolyl, R = nPr ( 2 ); X = Np-tolyl, R = tBu ( 3 ) as the major product. In the case of X = O, the minor hydrolysis product {[VO(OnPr)]2(µ-O)L}2 ( 4 ) has also been characterized. Complexes ( 1 )–( 4) , in the presence of the co-catalyst dimethylaluminum chloride and the reactivator ethyltrichloroacetate, are highly active (=16,400 g/mmol h bar), thermally stable pro-catalysts for the polymerization of ethylene. The use of silica supports with ( 1 ) and ( 2 ) under slurry conditions yielded polymer with activities =30 g/mmol h. Complexes ( 1 )–( 3 ) have also been screened as pro-catalysts for the ring-opening polymerization of e-caprolactone; the conversion rate order ( 1 ) (94%) > ( 2 ) (46%) > ( 3 ) (20%) was observed at 80 °C over 72 h.

Item Type:	Article
Faculty \ School:	Faculty of Science > School of Chemistry
Depositing User:	Rachel Smith
Date Deposited:	21 Jul 2011 10:18
Last Modified:	22 Nov 2022 14:30
URI:	https://ueaeprints.uea.ac.uk/id/eprint/34017
DOI:	10.1021/ic2010198

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